Insulation assemblies and, more particularly mineral fibers, including fibrous glass insulation assemblies are known in the art. Fibrous insulation assemblies are used for insulating buildings. The insulation assemblies take the form of batts or rolls which are compressed for packaging and transport. Many prior art insulation assemblies are sized along their side edges by slicing or cutting the side edges to the desired shape and width.
In contrast to textile and reinforcement fibers, glass wool fibers are produced by processes which generate noncontinuous fibers of random lengths. Glass wool products are best known for their properties such as thermal or acoustical insulation, and as filtration media.
Various glass compositions have been used for wool products. Factors affecting the choice of the glass composition are the availability and cost of the raw materials, the melting cost, the forming process used (glass liquidus and viscosity requirements), and the product properties (durability, resilience). For example, the low-cost rock and slag wool compositions have a high liquidus and therefore cannot be formed by the rotary process. These compositions are fiberized instead by an air blast process or a rotating disk or multiple rotating drum process, resulting in a high-shot (droplets of glass that have not been fiberized) content.
Due to the high surface area of the wool fibers, the glass must be resistant to water attack and, for some applications have good chemical durability.
The most familiar application for wool products is for thermal insulation. The random intertwining of many small fibers effectively traps air within the insulation pack, thus providing the insulating properties. Also, the fibers tend to block radiative heat transfer due to their optical properties. The characteristics of fire resistance, chemical stability, and resistance to moisture attack make glass an ideal material for this application.
The same ability to trap air makes glass fiber a suitable acoustical insulation. This has led to the use of glass fiber as ceiling and wall panels in buildings and vehicles, and to its use in air handling systems where noise control is important.
The fiber diameter of the wool products is an important indicator of its performance. In general, finer fiber products are more costly to produce, but provide better thermal and acoustical performance per pound of glass. Current technology can produce average fiber diameters that range from about 1 to 25 um. In a wool pack, the fiber diameter will vary considerably from the average value.
In most glass wool products, a phenolic binder is added during the manufacturing process to bond the mat together. Depending on the application, the amount of binder can vary between 4 and 15 percent by weight.
The present method of use is directed to an improvement in the recycling of fibrous glass insulation, in order to reduce thermal conductivity and improve product appearance.